Improvement in the manufacture of paraffine a



UNrTEn STATES HERBERT W. o. 'TWEDDLE, or PITTSBURG, PENNSYLVANIA.

lMPROVEMENTlN THE MANUFACTURE OF PARAFFINE AllD PARAFFINE OILS.

Specification forming part of Letters Patent No. 99,97'5 dated February15, 1870.

To all whom it may concern Be it known that I, HERBERT W. O. Twan- DLE,of the city of Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in theManufacture of Paratfine and .Paraffine Oils; and I do hereby declarethe following to be a full, clear, and exact description thereof. i

My invention relates tothe distillationof petroleum or other hydrocarbonoils, which can be made to yield a considerable percentage ofparat'fine; and consists in so carrying on the process of distillationthat little or none of the paraffine will be decomposed, but most or allof it will pass over as vapor, and condense'in the distillate, fromwhich it may then be separated by cold and pressure. Previous to thedate of my invention, the efforts of oil-manufacturers were chieflydirected to securing from the crude oil the largest possible percentageof illuminating-oil, in which oil the presence of paraffine wasobjectionable.

Since the early history of oil distillation, a fire-heat of hightemperature has been commonly applied to the outside of the still. Whenfrom forty-five to sixty per centum of the oil'was thus distilled over,the distillate marked 43 'or 44: Bauni hydrometer, and

was yellow in color and objectionablein odor.

In order to obviate these objections, various devices were adopted, suchas high domes,-

goose-necks, &c., the immediate object being to decompose the heavieroils, which contained the parraffine, and prevent them from passing overinto the condenser, as a result of which change the product was madelighter, both in gravity and color. By the use of such appliances, thevapors of the heavier oils, which contain the paraffine, are condensedin the dome or goose-neck and fall back into the still, Where they aredecomposed by the high and destructive temperature of the fire, a partgoing over and being condensed into light illulninatin g oil, almostcolorless, and a partforming carbides of hydrogen or othernon-condensable gases and water, and another portion being precipitatedor adhering to the sides or top of the still as solid carbonaceousmatter.

The residuum left in the stills as the result of such process ofdistillation (of which residuum the carbonaceous matter last referred toformsa largepart) amounts to from three to ten per cent. of the oildistilled, and which sometimes existsin a tarry mass, or may be reducedto. a coke. If this residuum be distilled rapidly by fire-heat in largequantities, it will produce oils from 43 gravity down to 24 or 200 Baum,which oils,'when chilled and submitted to pressure, yield from eight andone-half to twelve pounds of pure paraffine per barrel of residuum, orfrom forty to sixty pounds per one hundred barrels of crudepetroleum.Such parafline so produced is at first ofa-dark olive green color, andthe oil pressed out is 'heavy,' of ofl'ensive odor, and has acharacteristic blue I orgreen color. Then a subsequent'seve're andexpensive chemical treatment is required todecolorize both the paratfineand oil, and'to' somewhat deodorize the oil. p

4 At'ter being thus purified sdch oils are use as lubricants; but theyare very deficient in body, and contain animal or vegetable oils, whichcompounds assume, to a great extent, the blue and green tint abovereferred to, which, in commerce, is objectionable, and pal-affine oilsthus made do not command a ready sale for the above reasons. 9

My improved mode of producing paraffine and lubricating oil is, as aprocess, directly the reverse of that abovedescribed. Instead ofdecomposing the. paraffine, I so carry on the distillation as to preventsuch decomposition as far as possible. In this process I distil with acomparatively low heat produced by free steam superheated or not atpleasure in a vacuum, or a partial vacuum, with or without a tire on theoutside of the still, by which means I-am enabled to'produce paraffinein large quantity, and a superior quality of Inbricating-oil, both ofwhich are of marketable quality, and in fit condition for use, requiringbut little further chemical treatment.

To enable others skilled in the art to make use of my invention, I willproceed to describe the same.

The crude petroleum or other hydrocarbon,

having first been deprived of its lighter ingredients, such as gasoline,benzine, &c., by steam distillation or otherwise, is admitted intc avacuum-still of such constructlon as to permi-t=the vapors ofdistillation to flow over freely ,,or, be drawn over, so that they,shall not condense before leaving the still.

By a perforated pipe, or in other suitable manner, I admit steam, commonor superheated, into the body of thestill, keeping up at the sametime,by suitable appliances,- a partial or nearly complete vacuum. Inconnection with the steam-heat a'moderate fire V heat may be applied tothe outside of the still in any of the Ways known to the art.

The process of distillation is carried on till'from thirty-eight toforty-eight per cent."of the crude material is driven off, which beingcondensed gives illuminating-oil as a product, at which point thedistillation shows a gravity of about becomes richer and richer inparafiine as the distillation goes on, The condenser must H be kept warmwhile this is going on, or the parafline will solidify andclog theapparatus. After thel'distillation is finished, andparaffine ceases tocome over, the residuum will be found to contain very little paraffine.The

distillation is then chilled and pressed. The

oil being expressed there remains paraffineof a good color, requiringvery little further treatmentprevious to use. Com monl y remelting,rechilling, and repressing will sufiice to remove all deleterious orobjectionable impurities, and produce a pure article of paraffine. Inthis way [obtain from eight tosixteen pounds of almost chemically pureparaffine per barrel of crude petroleum, the chief reasonot' this largeryield being that in this pro cess the paraffine vapors are formed by acomparatively low temperature, carried over freely, and condensedwithout being decomposed in y the still.

The oils which, in the process described, are expressed from theparaffine product are for lubricating purposes vastly superior to thelubricating oils produced by the tarry raiduum of the old process, or ifmade direct from petroleum by direct fire. Though of less gravity,averaging 30 to 35 Baum, they have a much better body. They have but aslight pungent odor, which is easily and al most wholly removed by aslight subsequent chemical treatment, and have hardly a trace of theblue or green tint which is a distinctive characteristic and anobjectionable feature of lubricating-oils made by the ordinary process.The almost entire absence of the blue and yellow tint and offensive odorrenders this oil, which I have introduced in commerce as neutral topazoil, much more valuable than is a specific productof this mode orprocess of manufacture, and cannot be made 1n any other way. By thequalities specified it is readily distinguishable, by any one skilled inthe art, from'all other lubricating oils heretofore known to the trade.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The process of producing paraffine, hereinbefore described, by anexhaustivedistillation of the heavy oil at a comparatively lowtemperature, by the use of steam in avac'uumstill, with or without afire-heat, so as to drive over the parafline vapors undecomposed,substantially as described.

2. The production, by the process hereinbe fore described, of alubricating-oil as a new article of manufacture, possessingthedistinctive and distinguishing features above set forth, viz., almost.entire freedom from the blue and green tints which characterize theparaffine oils of commerce.

3. The use, in the distillation of oil, of a vacuum or partial vacuum,in connection with steam, common or superheated, inside the still,

and an'auxiliary fire outside, substantially as described. a Intestimony whereof I, the said HERBERT W. (J. TWEDDLE, have hereunto setmy hand.

HERBERT W. O. TWEDDLE.

Witnesses:

W. BAKE ELL, A. S NIoHoLsoN.

